Air conditioning



J1me 1965 J. w. KREUTTNER ETAL 3,

AIR CONDITIONING 3k 2 Sheets-Sheet 2 Filed May 3, 1962 l/ff/ I United States Patent hio Filed May 3, H62, Ser. No. 192,223 2 (Ilaims. (Cl. 16522) The present invention relates to air conditioning systems, and particularly to an induction type air conditioning unit and method of operation thereof.

It is known to supply conditioned primary air to a room or zone to be controlled through a distributing unit within the room or zone, the distributing unit being supplied with said primary air from a central source. It is also known to employ an air heating or cooling heat exchanger element within the room or zone adjacent to or in the distributing unit. Such is arranged so that secondary or recirculated air from the room is induced by the flow of primary air through the distributing unit to flow over the heating or cooling heat exchanger unit.

In prior arrangements, the primary air has been relatively constant in volume and temperature, while the room or zone control has been through the unit heat exchanger by varying fluid flow or by air bypass. This usually necessitates some degree of zoning and change over of control seasonally and hourly.

One of the objects of the present invention is to provide an air conditioning system having the advantages of both dual duct and induction unit systems, to simplify control requirements and provide inherent flexibility. Thus the dual duct primary system can provide complete control of all spaces with reduced equipment capacity for most of the year. ondary circulation through the heat exchanger can boost capacity, especially cooling capacity, to the required amount with control remaining in the double duct system.

in one aspect of the invention, a distributing device or box is provided for each room or zone. Warm and cold primary air is supplied from the usual dual duct central conditioning means through ducts to a control valve or damper means for proportioning the Warm and cold air to provide the desired zone temperature. A volume regulator receives the mixed proportioned air and discharges it at constant volume into the primary air inlet of the distributing device where it flows through a nozzle or an induction means to the distributing device. The distributing device is provided with a recirculated air inlet which has heat exchanger means adjacent thereto, preferably within the device. The air induction means is arranged so that the primary air flowing therethrough will pull zone air to be recirculated into the distributing device and over the heat exchanger, the controlled constant volume primary air being mixed with the heated or cooled recirculated air and then discharged into the room. The heat exchanger may be fed with heating fluid or cooling fluid in accordance with the season.

By the use of the present invention, valves and other troublesome liquid control means, at the units, are eliminated. Where a predetermined small amount of fresh air is required or when air from other zones cannot be recirculated, such as hospitals, the present system provides a simple manner in which to accomplish the same. The system is particularly etiicacious where the dual duct system is of the medium or high pressure type.

The above, other objects and novel features of the invention will become apparent from the following specification and accompanying drawings which are merely exemplary.

In the drawings:

FIG. 1 is a perspective view of an air conditioning During peak load periods, the secildlddh Patented June 8, 1965 unit to which the principles or the invention have been applied.

FIG. 2 is a front sectional view of another form of the unit.

FIG. 3 is a sectional View taken in the direction of line 33 of FIG. 2.

The invention will be described in conjunction with a distributing unit in a zone or room to be conditioned, it being understood that any number of distributing units or devices can be used as needed in a zone or in a plurality of zones.

Referring to FIG. 1, housing It may include a header or plenum 11 mounted near the upper end of housing 16', header 11 including nozzle means 12 extending along the header for directing primary air through outlet grille at slot 13 into the zone to be conditioned.

The primary air is supplied to header 31 through passages 14 leadim from mixing chamber 15. Mixing chamber 15 may be adjacent the housing iii, such as under the floor, or may be Within the housing. Warm and cold air can be supplied from a central conditioning unit through ducts 16 and 17 as is known in a dual duct system to which this invention particularly applies. A valve or damper means 13 can be controlled by thermostat 19 to proportion or mix the warm and cold air as needed. The thermostat control can be of any suitable type, such as pneumatic or electric devices. A suitable damper arrangement is illustrated in U.S. Patent No. 2,720,151. Preferably, a volume regulator it is employed to keep a constant volume of air supplied to duct or passage 14. One type of volume regulator, using flexi'ole curtain means, is seen in U.S. Patent No. 2,890,716.

Housing it) may include a secondary or recirculated air grille or aperture 21 in one side wall thereof. Adjacent the recirculated air aperture 21 and at right angles thereto, is located heat exchanger 22 extending substantially over the entire area of aperture 21. Heat exchanger 22 may be of the conventional finned type with heat exchange medium or liquid lines 23, 2 for feeding liquid or fluid therethrough. The lines 23, 24- may be part of a closed system through which a constant volume or quantity of heat exchange fluid or liquid may be continuously passed by pump 25 from reservoir or supply means 26. Seasonally, the fluid flowing'through lines 23, 24 may be hot or cold, as desired, in accordance with whether reservoir 26 is heated or cooled. The heat exchange fluid preferably flows at a substantially constant volume and at a selected temperature through the exchanger.

The primary air is mixed and brought to the required temperature as called for by zone thermostat 19, the discharge of primary air through nozzle means 12 inducing flow of room air or recirculated air over the heat exchanger, the heated or cooled recirculated air then mixing with the primary air as it passes through casing and slot 13. The volume regulator means 2% keeps the volume of primary air constant. Thus, the temperature of the zone is governed by controlling the temperature of the mixed primary air by properly proportion-lug warm and cold air from the dual duct system without using any control elements to control flow of heat exchange fluid through heat exchanger 22.

Another form of distributing box is shown in FIGS. 2 and 3 wherein casing 36) has an adjustable slot 31 in the top wall. Warm and cold air ducts 32, 33 can be connected to a central dual duct air conditioning means. Damper 34 is movable by pneumatic motor 35 through adjustable connections 36, as on plunger 37. The damper is mounted so as to be pivoted about area or pivot point 38. Volume regulator 35% receives the mixed air from damper zone 4%. Volume may be controlled by any suitable device such as volume regulator shown in the aforementioned US. Patent No. 2,890,716, and may consist of one or more fiexible curtains 42, 43 which cooperate with apertured seats 41, 44, respectively.

The constant volume mixed air at a temperature governed by the room thermostat or control is fed to header of plenum 45 from where it passes through nozzle means 46. The nozzles 46 may consist of a plurality of nozzles or may be a slit. Heat exchangers 47, 48 may extend along at least part of the length of the casing and are on either side of nozzle means 46. As primary .air flows from nozzles 46, it will induce air to be recirculated from the room through aperture or grille 48A where it mixes with the primary air. The mixed primary and recirculated air is fed into the zone through slot 31. A suitable room or zone thermostatic control means 49 can be connected by air pipe 49 to the motor 35.

It should be evident that variations can be made in details of construction and arrangement of parts without departing from the spirit of the invention except as defined in the appended claims.

What is claimed is: p

1. In a dual duct air conditioning system having warm and cold air supply ducts from a central conditioning station, the combination including an air distributing device in a zone, said device having primary air inlet means communicating with said ducts, recirculated air inlet means and air outlet means, heat exchanger means in the path of air passing through said recirculated air inlet means, means for supplying heat exchange medium at substantially constant volume to said heat exchanger means at a predetermined temperature selected in accordance with required heating or cooling, air induction nozzle means in said device connected to said primary air inlet means for inducing flow of recirculated air through said device and over said heat exchanger means when primary air flows therethrough, damper means controlling the proportion of warm and cold air delivered to said primary air inlet means, constant volume regulator means operatively associated with said inlet means for receiving the proportioned warm and cold air and maintaining constant volume flow thereof to said distributing device, and means responsive to zone condition for operating said damper means.

2. A dual duct air conditioning system according to claim 1, wherein said constant volume regulator means is positioned immediately adjacent said damper means.

References Cited by the Examiner UNITED STATES PATENTS 2,287,267 6/42 Palmer 165123 X 2,793,812 5/57 McDonald 165-22 X 2,984,459 5/61 \Vaterfill 165-22 3,032,323 5/62 Church 165-123 CHARLES SUKALO, Primary Examiner. 

1. IN A DUAL DUCT AIR CONDITIONING SYSTEM HAVING WARM AND COLD AIR SUPPLY DUCTS FROM A CENTRAL CONDITIONING STATION, THE COMBINATION INCLUDING AN AIR DISTRIBUTING DEVICE IN A ZONE, SAID DEVICE HAVING PRIMARY AIR INLET MEANS COMMUNICATING WITH SAID DUCTS, RECIRCULATED AIR INLET MEANS AND AIR OUTLET MEANS, HEAT EXCHANGER MEANS IN THE PATH OF AIR PASSING THROUGH SAID RECIRCULATED AIR INLET MEANS, MEANS FOR SUPPLYING HEAT EXCHANGE MEDIUM AT SUBSTANTIALLY CONSTANT VOLUME TO SAID HEAT EXCHANGER MEANS AT A PREDETERMINED TEMPERATURE SELECTED IN ACCORDANCE WITH REQUIRED HEATING OR COOLING, AIR INDUCTION NOZZLE MEANS IN SAID DEVICE CONNECTED TO SAID PRIMARY AIR INLET 